Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 31 May 2023 09:51:51 +0200 | From | Thorsten Leemhuis <> | Subject | Re: [PATCH] x86/purgatory: Do not use fortified string functions |
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Kees, thx for looking into this.
Joan, thx for bisecting. I should have done this earlier myself...
On 31.05.23 02:33, Kees Cook wrote: > With the addition of -fstrict-flex-arrays=3, struct sha256_state's > trailing array is no longer ignored by CONFIG_FORTIFY_SOURCE: > > struct sha256_state { > u32 state[SHA256_DIGEST_SIZE / 4]; > u64 count; > u8 buf[SHA256_BLOCK_SIZE]; > }; > > This means that the memcpy() calls with "buf" as a destination in > sha256.c's code will attempt to perform run-time bounds checking, which > could lead to calling missing functions, specifically a potential > WARN_ONCE, which isn't callable from purgatory. > > Reported-by: Thorsten Leemhuis <linux@leemhuis.info> > Closes: https://lore.kernel.org/lkml/175578ec-9dec-7a9c-8d3a-43f24ff86b92@leemhuis.info/
Did a test build and booted it in a Vm, everything seems fine. So thx again and feel free to add:
Tested-by: Thorsten Leemhuis <linux@leemhuis.info>
Ciao, Thorsten
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